MD, PhD, MAE, FMedSci, FRSB, FRCP, FRCPEd.

Few alternative fads have survived as long as the current Kombucha boom. Since decades, it is being hyped as the best thing since sliced bread. Consequently, it has become popular and is now being promoted as a veritable panacea, allegedly curing asthma, cataracts, diabetes, diarrhoea, gout, herpes, insomnia and rheumatism and purported to shrink the prostate and expand the libido, reverse grey hair, remove wrinkles, relieve haemorrhoids, lower hypertension, prevent cancer, and promote general well-being. Kambucha is believed to stimulate the immune system, and help with HIV infection. And – sure enough – it is ideal for detox!!!

One author goes even further and lists no less than 17 indications:

It’s good for your gut:

1. Kombucha contains naturally fermenting probiotics that help maintain healthy gut flora by increasing the number of beneficial organisms.
2. It preserves nutrients and breaks them down into an easily digestible form, which allows you to absorb them better.
3. It enhances the absorption of minerals, particularly calcium, iron, zinc, magnesium, phosphorous and copper.
4. Healthy gut flora improves digestion, fights candida overgrowth, improves mental clarity and stabilizes moods.
5. A healthy gut can also be attributed to reducing or eliminating depression an anxiety.
6. Kombucha contains numerous strains of yeasts and up to 20 different bacterial species (and possibly many more!).

It detoxifies the body:

7. The enzymes and bacterial acids in kombucha ease the burden on the liver by reducing pancreatic load.
8. Kombucha contains glucuronic acid, which binds to toxins and increases their excretion through the kidney or intestines.
9. In 1951, a popular Russian study found that the daily consumption of kombucha was correlated with an extremely high resistance to cancer.
10. It contains vitamin C, a potent detoxifier.

It supports the nervous system:

11. Kombucha contains vitamin B, which has been associated with reducing blood pressure and supporting the nervous system.

It’s anti-ageing and supports the joints:

12. Kombucha contains glucosamines, which are vital for the treatment and prevention of arthritis.
13. Kombucha allegedly eliminates grey hair, increases sex drive and improves eyesight.
14. Kombucha concentrates the antioxidants found in tea. Antioxidants not only fight the environmental toxins known as free radicals, which contribute to illness and disease, but help slow the aging process.
15. Theoretically, powerful antioxidant nutrients can prevent and lessen wrinkles by promoting skin elasticity.

It’s anti-microbial

16. Kombucha is anti-microbial due to it’s acetic and organic acids, proteins, enzymes and bacteriocins. It exerts anti-microbial activity against pathogenic bacteria like E coli and Salmonella. Incidentally, green tea kombucha has a high anti-microbial effect than when made with black tea.

It decreases sugar cravings

17. Emmet from Remedy told us that customers often comment that kombucha reduces their sugar cravings. “My take on this is that kombucha provides a natural energy boost and is therefore a handy antidote for when cravings kick in. It’s also a great way to break the soft drinks habit.”

END OF QUOTE

Sadly, none of these claims are based on anything that even vaguely resembles evidence. My own systematic review of 2003 aimed at locating and critically evaluating all human medical investigations of kombucha regardless of study design. However, no clinical studies were found relating to the efficacy of this remedy. Several case reports and case series raise doubts about the safety of kombucha. They include suspected liver damage, metabolic acidosis and cutaneous anthrax infections. One fatality was on record. I therefore concluded that on the basis of these data it was concluded that the largely undetermined benefits do not outweigh the documented risks of kombucha. It can therefore not be recommended for therapeutic use.

Since then no clinical trials have been published; but more information on the risks of Kombucha has emerged. A case report of a 54-year-old asthmatic woman, for instance. She presented to hospital with a 10-day history of breathlessness. On examination, she was tachypnoeic with mild wheeze. She had preserved peak flows and was saturating at 100% on room air. Investigations revealed severe metabolic lactic acidosis. On further questioning, it transpired that she drank kombucha tea, which has been linked to lactic acidosis. She made a full recovery with supportive management and cessation of the tea.

A case of hepatotoxicity has also been related to Kombucha consumption. Another case report tells the story of a 22 year old male, newly diagnosed with HIV, who became short of breath and febrile within twelve hours of Kombucha tea ingestion. He subsequently became combative and confused, requiring sedation and intubation for airway control. Laboratories revealed a lactate of 12.9 mmol/L, and serum creatinine of 2.1 mg/dL. The authors concluded that consumption of this tea should be discouraged, as it may be associated with life-threatening lactic acidosis.

But how can a simple tea like Kombucha cause such serious problems? The answer lies in the method of preparation which carries the risk of contamination: the Kombucha material is incubated at room temperature in a sugar-containing liquid for 7–12 days. It is hardly surprising that, under such conditions, human pathogens may grow. It follows that, depending on the method of preparation and standards of hygiene, some Kombucha teas may be entirely innocent whilst others carry the risk of contamination and infection. Contaminated batches may act like a ‘biological chain letter’.

Considering all this, here are my instructions for making Kombucha and enjoying it safely.

You will need:

  • 3 litres of filtered water
  • 10 green or black teabags
  • 1 SCOBY (symbiotic culture of bacteria and yeast)
  • ½ a cup of sugar

And this is what you need to do:

Boil the filtered water.

Pour over the teabags in a large container.

Add the sugar to the tea, and allow time to brew and cool (about two hours).

Pour the brewed tea into a large, jar and add the SCOBY.

Cover jar with cheesecloth, muslin or paper towel and secure with a rubber band.

Leave to brew for a week or more to taste.

Pour the kombucha into bottles

… and bin the lot.

12 Responses to Kombucha: hype, harm and humbug

  • We have strict recycling policies in my city and binning the bottles is a no-no. . I would drop the “Pour the kombucha into bottles” instruction and just pour it down the drain.

    The food historian, Rachel Lauden, points out that a healthy, fermented food source is beer. Well, it was, not sure about some of today’s brews.

    And what is wrong with saurkraut?

    I think I’ll give kombucha a miss even if it does work for grey hair.

    • I hope people realize that the writer is not a subject matter expert on kombucha or claims of benefits or harmful effects. ANYTHING consumed can be harmful icontrols arent in place for quality/stamdard products, processing, and handling in addition to controlling other variables too numerous to mention. Allergies and medications are also risk factors.
      Compared to apple cider vinegar kombucha, if brewed in a consistent environment for healthy fermentation is often more enjoyable and tolerant than the vinegar.
      True, uncontrolled studies are not available however historically this beverage like others is a healthier alternative to soda pop or sugary juices

  • Pour it into the compost?

  • I appreciate trying to present available data, which is quite limited, but it doesn’t appear your review was systematic based on Prisma or Cochrane guidelines. Your literature was helpful, and I appreciate the use of qualitative research methods. Kombucha, like the majority of things in life, should be enjoyed in moderation. The use of case-reports as “evidence” in the place of non-existent RCTs, case control, or other stronger evidence is equally limited.

  • I do Since I started Drinking two a day. I have bad stomach history and I haven’t gotten one in almost 2 years. I’m regular. So I will keep doing what I am doing. Denise

  • I’m really torn on this. I love my homemade kombucha, but I do worry about contamination.

  • Kombucha: How to fail at homebrewing 😀

  • Prof Tim Spector and Dr Michael Mosley appear to disagree with your findings ..

    • Ahhhhh
      That’s what Mosley stated: “There haven’t been that many proper scientific trials looking at the benefits of kombucha itself but…”

  • Completely respect your findings on kombucha Ernst however I do think it’s worth your while having a word with professor Tim Spector on the matter to hear the other side of the story..

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